The role of Emotion Dysregulation in Non-Suicidal Self-injury and Borderline Personality Disorder: Predictors and Mechanism-Based Treatment Approach

Abstract

[eng] Emotion regulation refers to the ability to modulate one's emotional responses effectively, while emotion dysregulation reflects a persistent difficulty in managing emotions, often leading to maladaptive coping strategies, such as non-suicidal self-injury (NSSI). NSSI is defined as the direct and deliberate harm to one's body tissue without suicidal intent, and presents a significant public health challenge. Its strong association with mental health problems, particularly in young people, and its prevalence in borderline personality disorder (BPD) underscore the need for effective interventions. While emotion dysregulation is strongly implicated in both NSSI and BPD, the specific dimensions of emotion dysregulation that characterize high-risk NSSI subgroups remain unclear. In addition, mindfulness skill training, a core component of Dialectical Behavior Therapy (DBT), shows promise in enhancing emotion regulation for individuals with BPD, yet the mechanisms driving its effectiveness require further investigation. This research project comprising five studies aimed to address these gaps, exploring the complex interplay between emotion dysregulation, NSSI, and BPD. The initial two studies focused on characterizing NSSI and identifying risk factors. Study 1 revealed a direct link between non-acceptance of emotions and the function of NSSI, while a lack of emotion regulation strategies was associated with NSSI frequency. Study 2 identified a subgroup characterized by severe NSSI, heightened emotion dysregulation, and low perceived social support. This profile was associated with a greater risk for psychopathology both at baseline and at the two-year follow-up. These findings highlight the heterogeneous nature of NSSI and the need for personalized treatment approaches. ABSTRACT 13 The subsequent studies examined the mechanisms of change underlying mindfulness-based DBT skill training. Study 3 demonstrated that mindfulness skill training reduced borderline symptoms by enhancing decentering—the ability to observe thoughts and feelings non-judgmentally—which, in turn, led to decreased emotion dysregulation. Studies 4 and 5 further explored the dynamic relationship between mindfulness skills and emotion regulation in BPD. Commitment to mindfulness skill practice was associated with reduced emotion dysregulation, with a minimum effective dose of ≥ 3 days and more than 30 minutes in total per week, identified as crucial (Study 4). Notably, greater within-person effects of nonjudging the inner experience and body awareness at a given week predicted subsequent improvements in emotion regulation at the following week. Decentering moderated this associations, with stronger effects observed in those with higher decentering capacity (Study 5). Importantly, a bidirectional relationship between mindfulness practice, the proposed mechanisms of change, and emotion dysregulation was consistently observed. This research program provides valuable insights for both research and clinical practice. By identifying specific emotion regulation difficulties associated with NSSI and highlighting high-risk profiles, this work informs more targeted prevention and intervention strategies. Additionally, by elucidating the mechanisms through which mindfulness-based DBT skills training impacts emotion regulation – particularly the roles of decentering, non-judgmental awareness, and body awareness – this research offers clinicians valuable tools for optimizing treatment protocols. Lastly, the identification of a minimum effective dose of mindfulness practice and the recognition of a bidirectional relationship between mindfulness practice and emotion dysregulation underscore the need for flexible and individualized treatment approaches.

[spa] La desregulación emocional (DE), la dificultad para controlar las emociones de manera efectiva, puede desencadenar conductas desadaptativas, como la autolesión no suicida (ANS), que consiste en un daño corporal deliberado sin intención suicida. Sin embargo, las dimensiones específicas de la DE que caracterizan a subgrupos con ANS severa aún son inciertas. Por otro lado, el entrenamiento en mindfulness, componente clave de la Terapia Dialéctica Conductual (TDC), ha demostrado ser eficaz en la reducción de la DE en el TLP, incluyendo las conductas de ANS. Aun así, los mecanismos subyacentes a sus efectos permanecen poco estudiados. Este proyecto, compuesto por cinco estudios, exploró la interacción entre la DE, ANS y el TLP. El Estudio 1 reveló que la no-aceptación de emociones se asoció con la motivación por ANS, mientras que la carencia de estrategias de regulación emocional se asoció con la frecuencia de ANS. El Estudio 2 identificó un subgrupo de ANS severa, caracterizado por alta DE y bajo apoyo social percibido. Este subgrupo presentó un mayor riesgo de psicopatología tanto al inicio como en el seguimiento a dos años. Los estudios posteriores examinaron los mecanismos de cambio subyacentes al entrenamiento en mindfulness. El Estudio 3 demostró que el entrenamiento redujo los síntomas límite al mejorar el descentramiento (la capacidad de observar pensamientos y sentimientos sin juicio), lo que a su vez disminuyó la DE. El estudio 4 encontró que una dosis mínima de ≥3 días y más de 30 minutos semanales de práctica de mindfulness eran necesarios para reducir la DE en el TLP. Específicamente, un mayor efecto intra-persona de no juzgar la experiencia interna y una mayor conciencia corporal redujeron la DE, mientras que el descentramiento moderó estas asociaciones (Estudio 5). Finalmente, se observó una relación bidireccional entre las habilidades de mindfulness y la DE. Este estudio identificó dificultades específicas de la DE asociadas con la ANS y resaltó perfiles de alto riesgo. Además, los resultados esclarecen los mecanismos por los cuales el entrenamiento en mindfulness mejora la DE. Estos hallazgos ofrecen información relevante para optimizar los protocolos de prevención y tratamiento, así como desarrollar intervenciones personalizadas y flexibles.